Apparatus for excavating, shoring and backfilling a trench

ABSTRACT

A screw auger is operated at the bottom of an excavation for undercutting and dislodging the earth while shoring members are being inserted into the ground. The screw auger is associated with a conveyer system for removing the dislodged earth from the excavation.

United States Patent H011 1451 Sept. 9, 1975 [54] APPARATUS FOR EXCAVATING, SHORING 1,303,399 5/1919 Ryan 37/82 UX AND BACKFILLING A 1,740,923 12/1929 Jaeger 1 37/87 1,814,094 7/1931 Rhodes. 37/80 R Inventorr Edward J- e 320 Warwwk 2,222,437 11 1940 Lykken 37 195 x South Orange, NJ. 07079 2,705,379 4/1955 Fruhling 37/81 3,319,364 5/1967 Evans 37/86 [22] Flledl 1973 3,513,572 5 1970 Novet 37/103 NO: 3,524,510 8/1970 Connell 37/1316, 6 3,606,757 9/1971 De Weese et a1 61/41 A 52] US. Cl. 37/82; 37/1425; 61/41 A; FOREIGN PATENTS OR APPLICATIONS 61/72.1; 175/62; 175/91; 175/393; 299/65 1,531,318 5/1968 France 37/82 [51] Int. Cl. E021 3/06; E02f 5/04 [58] Field of Search 37/80 R, 81, 82, 142.5, Primary ExaminerC1ifford D. Crowder 37/195, 87, 103, DIG. 6, 191, 192, 86; 61/41 Attorney, Agent, or Firm-Marvin A. Naigur R, 41 A, 72.1; 299/44, 65, 66; 175/62, 91, 393

- 57 ABSTRACT [56] References cued A screw anger is operated at the bottom of an excava- UNITED STATES PATENTS tion for undercutting and dislodging the earth while 96,824 11/1869 McGehee 37/82 shoring members are being inserted into the ground. 684,762 10/19O1 Taylor A n 37/32 The screw auger is associated with a conveyer system 799353 9/1905 0 Connor 37/82 for removing the dislodged earth frorn the excavation. 847,587 3/1907 Locke 175/393 X 1,113,318 10/1914 Edwards 37/1425 UX 5 Claims, 6 Drawing Figures PATENTEB SEP 9 I975 SHEET 1 UP 2 PATENTEU SEP 9 I975 miiET 2 BF 2 WNNAW w BACKGROUND OF THE INVENTION This invention relates generally to the excavation of trenches which have a variety of uses in the construction industry, such as for pipelines, sewer lines, water lines, gas lines and the like. It is usualfor suchtrenches to be excavated to depths in the neighborhood of feet, and the practice has been to excavate these rela tively deep trenches by means of man-operated earth moving equipment. Also, separate earth shoring equipment has been utilized to prevent the walls of the trenches from caving in. The prior methods and apparatus for constructing pipeline trenches were not only difficult and time consuming, but also resulted in a substantial number of injuries and fatalties to the construction workers involved. The present invention provides a method and apparatus for continuously excavating a trench without the need for man-operated equipment in proximity to, the trench being excavated. This is accomplished by a screw auger which is positioned at the bottom of the trench which is being excavated, such that the earth can be undercut and removed from the trench by means of a diagonally disposed conveyer system. A further horizontally disposed conveyer means is provided for returning the earth to the previous trench section which had been excavated. Also, means are provided for inserting non-interlocking steel shoring members simultaneously with the undercutting of the trench. Thus, the trench excavation operation of the present invention is virtually continuous and automatic and eliminates the need of operating personnel in proximity to potentially dangerous areas. Furthermore, by introducing fluid simultaneous with the undercutting operation, it is possible to operate in various types of soil conditions, such as clay or mud, which have a tendency to clog the screw auger and prevent the earth from being moved freely. Thus, the apparatus and method of earth excavation of the present application afford a virtually automated system for excavating continuous trenches. This results in the elimination of the various heavy equipment which has heretofore been necessary, such as pile drivers, cranes, backhoes and trucks. Further, the congestion noise and vibration attendant to the use of this type of equipment at street level is eliminated, thereby avoiding the noise and air pollution problem.

SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWINGS The above brief description, as well as further objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of a presently preferred, but nonetheless illustrative embodiment in accordance with the present invention, when taken in connection with the accompanying drawings wherein:

1 FIG. 1 is a side elevational view of a trench in various stages of excavation, showing the earth excavation equipment of the present invention in operation;

FIG. 2 is an enlarged plan view of the earth shoring panels and guide rails shown in FIG. 1;

FIG. 3 is an enlarged perspective view of a portion of the screw auger of FIG. 1, which shows the means of introducing fluid into the area being undercut;

FIG. 4' is a horizontal sectional view taken through the line 44 of FIG. 1 to show the position of the shoring panels prior to the initiation of the undercutting operation;

FIG. 5 is a horizontal sectional view taken through the line 55 of FIG. 1 to show the position of the shoring panels and the earth cutting auger during the undercutting operations; and

FIG. 6 is a horizontal sectional view taken through the lines 6--6 of FIG. 1 to show the position of the shoring panels and the pipeline member after the trench has been backfilled.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to FIG. 1, there is shown a trench excavating apparatus generally designated by the reference numeral 10, that is located in a continuous trench 12, which is defined by an upper surface level line 14, an intermediate surface level line 15, and a bottom level line 16. The initial procedure in excavating the trench 12 is usually to first dig a pilot cut trench 18 which extends from the ground level line 14 down to a pilot cut line 20. The pilot cut trench 18 is generally dug by a back hoe in order to make certain that no existing underground lines will be damaged or broken, and the pilot out line 20 usually does not extend more than 10 feet from the surface level line 14.

By progressively comparing FIGS. 1 and 5, it can be appreciated that the earth excavating apparatus 10 includes a diagonally disposed screw conveyer and a horizontally disposed cutting auger, which are generally designated 24 and 26, respectively. It should be understood that the cutting auger 26 may also be planed in an inclined position. The cutting auger 26 consists of a motor 28 for powering a drive shaft 30 which is integrally formed with first continuous helical screw threads or flytes 32 and second continuous helical screw threads or flytes 34, which are separated by a cylindrical shaft section 36. The cylindrical shaft section 36 corresponds to a central position, toward which the earth is conveyed as indicated by the opposing directional arrows which have been designated 38 and 40, respectively. As best shown in the angle diagram of FIG. 1, the screw flytes 32 are formed with a helix angle 42 which is equal but opposite to the helix angle 44 of the screw flytes 34.

The screw conveyer 24 consists of a chute 46, which extends from central position 36 to the surface level line 14, and a drive shaft 48 that is integrally formed with helical screw threads or flytes 50. A horizontally ber 56 which is in flow communication with a source of compressed air 58. Thus, internal chamber 56 is defined by the hollow control bore of drive shaft 30 and the hollow interior of helical screw flytes 32 and 34 that are formed with through holes 60. Air under pressure is passed by means of the compressor 58 into the internal chamber 56 and out of the through holes 60, such that the earth is prevented from adhering to the screw flytes 32 and 34. It should be noted that any fluid under pressure such as water can be passed into the internal chamber 56.

Shoring walls, generally designated 60 in FIG. 1, include first shoring panels 62 which are positioned along pilot out line 20, second shoring panels 64 which are positioned along intermediate surface level during the operation of earth excavating apparatus 10, and third shoring panels 66 which are completely imbedded after the backfilling operation has been completed. The shoring panels 62 and 64 are maintained in a fixed position by means of opposing guide rails 68 and 70, respectively. The guide rails 68 and 70 are each formed with vertical flanges 72, which are separated by an elongated central plate 74. The shoring panels 62, 64 are maintained in spaced relationship with respect to the guide rails 68, 70, by means of a plurality of roller assemblies 76 which are securely positioned on the inner vertical flanges 72. Each roller assembly 76 consists of a hanger bracket 78 which is mounted on the vertical flanges 72 and a U-shaped carrier 79 which is fixed to the hanger bracket 78 for rotatably receiving a guide wheel 80. The hanger brackets 78 are designed to slideably engage the vertical flanges 72, so as to be moved into the proper position for guiding the shoring panels 62 and 64, and any known means of securing the hanger bracket 78 can be used, such as set screws, wedges or the like, which have not been shown in the drawings for the sake of simplicity.

By progressively inspecting FIGS. 1 and 4, it can be appreciated that the outer guide rails 70 are positioned at the surface level line 14, and the inner guide rails 68 are maintained in position by means of a bracket 81 extending from outer guide rail 70 to inner guide rail 68, and a spacer section 82 is provided for added bracing, as well as for supporting the belt conveyer 52. For mounting a pair of guide beams 84 directly below the inner guide rails 68, a pair of vertical supports 86 are secured between guide beams 84 and guide rails 68. The guide beams 84are maintained in a fixed position by means of lower spacer beams 86. A pair of motor driven winches 88 are mounted on the guide beams 84 for entraining a cable 90 over a guide pulley 92 which is mounted on the outer vertical flanges 72 of the guide rails 68. The cable 90 is secured to a channel member 94 which is positioned at the top of shoring panels 64. It is preferable to provide a separate motor driven winch unit 88 for each end of the channel member 94, such that downward force can be exerted at the outer ends of shoring plate 64.

Prior to the operation of the trench excavating apparatus 10, the pilot trench 18 must be prepared, and it is then necessary to dig an opening excavation trench 12 in order to initially position the conveyer 24 and cutting auger 26. After this initial positioning has taken place, it is contemplated that the excavating apparatus 10 may operate continuously and virtually automatically, such that the dirt can be removed from the trench 12, and a pipeline designated 96 can be connected in place, with the dirt thereafter being backfilled in the trench 12, as shown in FIG. 1. Accordingly, during the rotation of the cutting auger 26, the earth along bottom level line 16 is undercut such that the intermediate surface level line 15 moves downwardly away from the upper surface level line 14. Thus, the earth along bottom level line 16 is dislodged and moved as shown by the directional arrows 38 and 40 toward the central position 36. The earth from central position 36 is taken out of the trench 12 by means of the diagonal conveyor 24 and is transferred onto horizontal conveyer 52 for back-filling the portion of the trench 12 in which the pipeline 96 has been completed.

It should be noted that the horizontal conveyer unit 52 can be provided with sets of wheels and axles for moving conveyer unit 52 along a set of tracks on the upper surface line 14. This wheel and axle arrangement which is not shown in the drawings could be in the form of wheels or rollers which would ride either on the outer guide rails or the inner guide rails 68. In this manner, the trench excavating apparatus 10 could be self-propelled to move horizontally with respect to upper surface line 14 while the auger 26 was undercutting the earth along bottom level line 16.

A latitude of modification, change and substitution is intended in the foregoing disclosure and in some instances some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the spirit and scope of the invention herein.

What is claimed is:

1. Apparatus for the continuous excavation of earth to form a trench defined by a lowermost surface and an uppermost surface comprising,

a cutting auger positioned below said uppermost surface for undercutting through the earth substantially along the horizontal central axis of said trench at said lowermost surface,

said cutting auger comprising a drive shaft integrally formed with a first continuous helical screw flyte, and a second continuous flyte formed with a helix angle opposite to the helix angle of said first continuous flyte,

said cutting auger being embedded in the earth substantially along the entire length of said auger and along said horizontal central axis of said trench such that the earth along said lowermost surface is dislodged and moved toward a central position between said continuous flytes, and

means for conveying the dislodged earth from said central position out of said excavation.

2. Apparatus according to claim 1, in which said drive shaft is formed with a cylindrical section in the location of said central position, for separating said first continuous flyte from said second continuous flyte.

3. Apparatus according to claim 1, in which said shaft and screw flytes are formed with an internal chamber, said sc'rew flytes having through holes, and means for introducing a fluid under pressure to said internal chamber, such that said fluid can be passed out of said through holes to prevent the earth from adhering to said screw flytes.

4. Apparatus according to claim 1, in which said conveying means is in the form of a diagonally disposed screw conveyer that extends from said central position to said uppermost surface, and a horizontally disposed conveyer that is positioned at said uppermost surface to receive the earth from said diagonal screw conveyer, whereby the earth which has been excavated can thereafter be backfilled.

5. Apparatus for the continuous excavation of earth to form a trench defined by a lowermost surface and an uppermost surface comprising,

a cutting auger positioned below said uppermost surface for undercutting through the earth substantially along the horizontal certral axis of said trench at said lowermost surface and said cutting auger embedded in the earth substantially along the entire length of said auger and along said horizontal central axis of said trench, such that the earth along said lowermost surface is dislodged and moved central position out of said excavation. 

1. Apparatus for the continuous excavation of earth to form a trench defined by a lowermost surface and an uppermost surface comprising, a cutting auger positioned below said uppermost surface for undercutting through the earth substantially along the horizontal central axis of said trench at said lowermost surface, said cutting auger comprising a drive shaft integrally formed with a first continuous helical screw flyte, and a second continuous flyte formed with a helix angle opposite to the helix angle of said first continuous flyte, said cutting auger being embedded in the earth substantially along the entire length of said auger and along said horizontal central axis of said trench such that the earth along said lowermost surface is dislodged and moved toward a central position between said continuous flytes, and means for conveying the dislodged earth from said central position out of said excavation.
 2. Apparatus according to claim 1, in which said drive shaft is formed with a cylindrical section in the location of said central position, for separating said first continuous flyte from said second continuous flyte.
 3. Apparatus according to claim 1, in which said shaft and screw flytes are formed with an internal chamber, said screw flytes having through holes, and means for introducing a fluid under pressure to said internal chamber, such that said fluid can be passed out of said through holes to prevent the earth from adhering to said screw flytes.
 4. Apparatus according to claim 1, in which said conveying means is in the form of a diagonally disposed screw conveyer that extends from said central position to said uppermost surface, and a horizontally disposed conveyer that is positioned at said uppermost surface to receive the earth from said diagonal screw conveyer, whereby the earth which has been excavated can thereafter be backfilled.
 5. Apparatus for the continuous excavation of earth to form a trench defined by a lowermost surface and an uppermost surface comprising, a cutting auger positioned below said uppermost surface for undercutting through the earth substantially along the horizontal certral axis of said trench at said lowermost surface and said cutting auger embedded in the earth substantially along the entire length of said auger and along said horizontal central axis of said trench, such that the earth along said lowermost surface is dislodged and moved toward a central position, means provided for inserting a pair of opposing individual shoring sheets into the earth in said excavation simultaneously with the operation of said cutting auger through the earth, each of said shoring sheets is positioned between opposing guide beams, said guide beams formed with opposing vertical flanges, and a plurality of guide rollers journaled on a vertical flange of each guide beam for contacting and guiding said shoring sheets, aNd means for conveying the dislodged earth from said central position out of said excavation. 